X-Envelope-From: m.j.watts@xxxxxxxxxxxx Mon Jun 27 22:28:33 2005
X-Original-To: tesla@xxxxxxxxxx
Delivered-To: tesla@xxxxxxxxxx
From: "Malcolm Watts" <m.j.watts@xxxxxxxxxxxx>
To: "Tesla list" <tesla@xxxxxxxxxx>
Date: Tue, 28 Jun 2005 16:28:32 +1200
Subject: Re: Newbie polyurethane mistake
Reply-To: M.J.Watts@xxxxxxxxxxxx
X-Confirm-Reading-To: M.J.Watts@xxxxxxxxxxxx
X-pmrqc: 1
Priority: normal
X-mailer: Pegasus Mail for Win32 (v3.12c)
Hi Tom,
On 27 Jun 2005, at 21:58, Tesla list wrote:
> Original poster: "Coyle, Thomas M." <tcoyle@xxxxxxxxxxxxxxx>
>
> Having never worked with polyurethane before, I made what I'm sure is
> a super-newbie mistake, and I'm wondering if there's any way to
> rectify it.
>
> I coated my secondary with about 7 coats of polyurethane (until I
> couldn't feel the ridges of the turns). Unfortunately, I didn't let
> each coat fully dry before putting the next one down. Now, the outside
> is rock-solid, but if you press with a finger, the coating will buckle
> and peel. The bottom layers are still gelatinous, while the top is
> solid. It's been sitting for 6 weeks while I work on other things, and
> that inside just won't dry (if I pick off some of the top, it's still
> moist below). This would seem to be a great testament to how wonderful
> polyurethane is at sealing out (or in) moisture.
>
> Is there any way to salvage this secondary? Can poly be baked to
> finish curing? Will the gelatinous poly cause flashovers or some other
> nastiness? Has anyone ever made this mistake before (say yes - it'll
> make me feel better)?
>
> Thanks,
>
> Tom
I'd just go ahead and use it. Baking might finish the drying but
unless you need to have it hardened it shouldn't matter. It shouldn't
be necessary to fill a coil up with varnish in that way. Note that
the only thing insulating each turn from the next is the insulation
on the wire.
Malcolm